Package org.assertj.core.api

Class Condition<T>

java.lang.Object
org.assertj.core.api.Condition<T>
Type Parameters:
T - the type of object this condition accepts.
All Implemented Interfaces:
Descriptable<Condition<T>>
Direct Known Subclasses:
HamcrestCondition, Join, MappedCondition, Negative, VerboseCondition
public class Condition<T> extends Object implements Descriptable<Condition<T>>
A condition to be met by an object.
Author:
Yvonne Wang, Alex Ruiz

  • Constructor Details

    • Condition

      public Condition()
      Creates a new Condition. The default description of this condition will the simple name of the condition's class.

    • Condition

      public Condition(String description)
      Creates a new Condition.
      Parameters:
      description - the description of this condition.
      Throws:
      NullPointerException - if the given description is null.

    • Condition

      public Condition(Predicate<T> predicate, String description, Object... args)
      Creates a new Condition with the given Predicate, the built Condition will be met if the Predicate is.

      You must give a description, it will be used to build a nice error message when the condition fails, you can pass args to build the description as in String.format(String, Object...).

      Example: 

       // build condition with Predicate<String> and set description using String#format pattern.
 Condition<String> fairyTale = new Condition<String>(s -> s.startsWith("Once upon a time"), "a %s tale", "fairy");

 String littleRedCap = "Once upon a time there was a dear little girl ...";
 assertThat(littleRedCap).is(fairyTale);
      Error message example: 
       // unfortunately this assertion fails ... but contact me if you can make it pass :)
 assertThat("life").is(fairyTale);
 // error message
 Expecting:
  <"life">
 to be <a fairy tale>
      Parameters:
      predicate - the Predicate used to build the condition.
      description - the description of this condition.
      args - optional parameter if description is a format String.
      Throws:
      NullPointerException - if the given Predicate is null.
      NullPointerException - if the given description is null.

    • Condition

      public Condition(Description description)
      Creates a new Condition.
      Parameters:
      description - the description of this condition.
      Throws:
      NullPointerException - if the given description is null.

  • Method Details

    • describedAs

      public Condition<T> describedAs(Description newDescription)
      Sets the description of the assertion that is going to be called after.

      You must set it before calling the assertion otherwise it is ignored as the failing assertion breaks the chained call by throwing an AssertionError.

      This overloaded version of "describedAs" offers more flexibility than the one taking a String by allowing users to pass their own implementation of a description. For example, a description that creates its value lazily, only when an assertion failure occurs.

      Specified by:
      describedAs in interface Descriptable<T>
      Parameters:
      newDescription - the new description to set.
      Returns:
      this object.

    • description

      public Description description()
      Returns the description of this condition.
      Returns:
      the description of this condition.

    • conditionDescriptionWithStatus

      public Description conditionDescriptionWithStatus(T actual)
      Returns the description of this condition with its status failed or success.
      Parameters:
      actual - the instance to evaluate the condition status against.
      Returns:
      the description of this condition with its status.

    • status

      protected Condition.Status status(T actual)

    • matches

      public boolean matches(T value)
      Verifies that the given value satisfies this condition.
      Parameters:
      value - the value to verify.
      Returns:
      true if the given value satisfies this condition; false otherwise.

    • toString

      public String toString()
      Overrides:
      toString in class Object